After taking much of last week off for the Thanksgiving holiday, the trial was to resume this morning in Suffolk Superior Court in Boston with the prosecution calling witnesses from Hill Holliday, the Boston advertising firm that created ads for the Lottery.

A Quincy resident, Cahill is charged with using Lottery commercials to advance his candidacy in the final weeks of his unsuccessful bid for governor in 2010 and gain an unwarranted privilege in violation of state ethics law.

His top aide, Scott Campbell, is also on trial, accused of being Cahill’s co-conspirator.

Prosecutor James O’Brien said he could wrap up Tuesday, but Judge Christine Roach called that an optimistic forecast, given that state prosecutors still want to call more employees from Hill Holliday to testify plus five other witness, including a forensics expert from the state Attorney General’s Office, a former Boston Herald reporter and a Lottery commissioner.

In the trial’s most recent action last Tuesday, prosecutors emphasized the resistance within the Massachusetts State Lottery to the planned 2010 ad campaign, which touted the Lottery’s management and not specific lottery games.

Lottery brass – including former state Lottery Director Mark Cavanagh, then-chief of staff Al Grazioso and marketing director Diane Anderson – “aren’t happy” with the planned $1.8 million ad campaign, Amy Hardcastle, the Lottery’s account manager at Hill Holliday, wrote in August 2010 to her boss, Mike Sheehan.

Sheehan responded in an email with the subject line titled, “Hide under your desk,” warning Hardcastle, “I told the Treasurer there was resistance at the Lottery and that we couldn’t proceed without signatures. He’s going to rip Al’s head off.”

Cavanagh, who is now Quincy’s chief financial officer, testified earlier in the trial how angry he was when Republicans bankrolled radio ads criticizing the Lottery as a way to undercut Cahill, who was threatening to take votes away from their candidate, Charlie Baker.

“They caught me off-guard,” Cavanagh said of the ads. “I couldn’t believe what I was hearing.”

While infuriated by the ads, which were funded by the Republican Governors Association, Cavanagh said he was also furious when asked to sign off on spending $1.8 million of the Lottery’s $2 million ad budget to counter them, at a time when Cahill was actively campaigning for governor.

“There was no, I think I said, ... way that I was going to sign that,” Cavanagh testified. “I think it was borderline illegal. ... I felt it was an exorbitant amount of money based on the amount of money that we had during the year.”